Net Income per Common Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Schedule of reconciliation of the weighted average basic common shares outstanding to weighted average diluted common shares outstanding

A reconciliation of the weighted average basic common shares outstanding to the weighted average diluted common shares outstanding is as follows:

	Three Months Ended				Nine Months Ended
(millions, except share and per share data) (unaudited)	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Net income attributable to SP Plus Corporation	$	11.2	$	7.0	$	33.4	$	13.5
Basic weighted average common shares outstanding	22,203,023		22,208,139		22,186,556		22,293,776
Dilutive impact of share-based awards	320,013		288,972		314,822		278,157
Diluted weighted average common shares outstanding	22,523,036		22,497,111		22,501,378		22,571,933
Net income per common share
Basic	$	0.51	$	0.31	$	1.51	$	0.60
Diluted	$	0.50	$	0.31	$	1.48	$	0.60